ZOOLOGY. 497 
Tue Warre-rumrep Surike.—In a residence of two years in 
central and southern Iowa, I killed a large number of shrikes, and 
although the greater number were plainly referable to Collurio 
excubitoroides, there were ‘some that 1 could not satisfactorily 
place as belonging either to C. excubitoroides or O. Ludovicianus,— 
they seemed to be intermediate between the two; generally nearer 
the former than the latter. Occasionally an individual would 
agree very nearly with Baird’s description of C. Ludovicianus, 
though without undoubted specimens of the latter bird from the 
southern states, I was unable to decide whether they were ab- 
solutely identical, or in what the difference consisted. I mention 
this fact to show that, while occasional observations, or observa- 
tions for a limited space of time, would probably result in the 
conclusion that O. excuditoroides was the only form, close and ex- 
tended observation would show a strong variation in many cases 
toward the C. Ludovicianus type, while ranely a specimen would 
be found that would appear to be absolutely of that species. 
Nevertheless, the typical excubitoroides is the predominating, and 
by far the commonest, form; nor could I observe anything in the 
habits of the birds pointing to two species or even well-defined 
varieties ; birds mated together sometimes showing considerable 
differences of plumage.—T. Martın Tripre, Orange, N. J. 
Tappotes iv Wiyrer.— An esteemed contributor sends us an 
account of tadpoles that were found early this spring, having 
passed the winter in that condition, which he considered as per- 
haps a case of arrested development. It is however well known 
that the large bull frog (Rana pipiens) is (at least in the New 
England States) two or three years in the larval or tadpole con- 
dition, and if retained in a tank and forced to keep up its fish-like 
life there is no knowing how long the larval state would be re- 
tained. The experiments made by Prof. Wyman several years 
Since resulted in keeping the tadpoles for a number of years, 
and at the end the water was accidentally let out of the tank. 
If any one will take the trouble of trying the experiment it will 
Probably be found that unless the tadpoles are allowed a chance 
to hop along shore about the time their legs are developed, they 
can be greatly retarded in obtaining their perfect form as frogs or 
toads. Many of our New England species of frogs and toads 
develop very rapidly, passing through the tadpole condition in a 
AMER. NATURALIST, VOL. VII. 32 
